Diffusion GnuPG 983f7b2acbd1

gpg: Fix out-of-bound read in subpacket enumeration

Authored by werner on Mar 15 2018, 8:44 AM.

Description

gpg: Fix out-of-bound read in subpacket enumeration

* g10/parse-packet.c (enum_sig_subpkt): Check buflen before reading
the type octet.  Print diagnostic.

If the final subpacket has only a length header evaluating to zero and
missing the type octet, a read could happen right behind the buffer.
Valgrind detected this. Fix is obvious. Note that the further
parsing of the subpacket is still okay because it always checks the
length. Note further that --list-packets uses a different code path
and already reported an error.

He provided a test file copied below. Running "gpg -v --verify" on it
triggered the bug.

-----BEGIN PGP ARMORED FILE-----
Comment: Use "gpg --dearmor" for unpacking
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qYZP

-----END PGP ARMORED FILE-----

  • Reported-by: Philippe Antoine
  • Signed-off-by: Werner Koch <wk@gnupg.org>

Details

Committed
wernerMar 21 2018, 7:43 PM
Parents
rG11bbd99477ef: scd: signal mask should be set just after npth_init.
Branches
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